高海拔隧道内防冻剂对混凝土强度影响分析

Analysis of Influence of Antifreeze on Concrete Strength in High Altitude Tunnel

在海拔较高地区的某隧道施工过程中,由于高原缺氧状态下昼夜温差较大,在完成洞内混凝土衬砌一个月内,发生了较长段的裂缝和变形。通过对混凝土内添加适合剂量的防冻剂来提高混凝土的强度,对于海拔约4000 m地区,养护条件对隧道内混凝土最终强度影响较大,分别在混凝土中掺配0%、2%、4%、6%比例的防冻剂,混凝土抗压强度均有所改变,综合考虑隧道内混凝土强度提升和投资成本等多重因素,最终得出当防冻剂掺配比例为4%的时候是最为经济合理的。将结论应用于实践,在衬砌C40混凝土内添加了4%比例的防冻剂,效果良好。

During the construction of a tunnel in a high-altitude area,due to the large temperature difference between day and night under the hypoxic state of the plateau,within a month of completing the concrete lining in the tunnel,a long period of cracks and deformation occurred.The strength of the concrete is improved by adding a suitable amount of antifreeze to the concrete.For an area of about 4000m above sea level,the curing conditions have a greater impact on the final strength of the concrete in the tunnel.The concrete is mixed with 0%,2%,4%,6%Ratio of antifreeze,the compressive strength of concrete has changed,considering the multiple factors of concrete strength improvement and investment cost in the tunnel,it is finally concluded that when the proportion of antifreeze is 4%,it is the most economical and reasonable.Applying the conclusion to practice,4%antifreeze is added to the lining C40 concrete,and the effect is good.